1-Iodobutane AA

CH₃CH₂CH₂CH₂I

Iodine

Nuclear Quadrupole Coupling Constants

in 1-Iodobutane AA

Click on GG, GA to view results for these conformers.

Calculation of the iodine nqcc tensor in the AA conformer of 1-iodobutane was made on a molecular structures obtained by MP2/6-311+G(d,p) and MP2/6-311+G(3df,3pd) optimization. These calculated nqcc's are compared with the experimental values of Arsenault et al. [1] in Table 1. Structure parameters are given in Table 2, rotational constants in Table 3, quartic centrifugal distortion constants in Table 4.

In Table 1, subscripts a,b,c refer to the principal axes of the inertia tensor, subscripts x,y,z to the principal axes of the nqcc tensor. ETA = (X_xx - X_yy)/X_zz. Ø (degrees) is the angle between its subscripted parameters.

RMS is the root mean square difference between calculated and experimental diagonal nqcc's (percent of the average of the magnitudes of the experimental nqcc's). RSD is the residual standard deviation of calibration of the B1LYP/6-311G(df,p) model for calculation of the efg's/nqcc's.


Table 1. ¹²⁷I nqcc's in AA-1-Iodobutane (MHz). Calculation was made on the followingstructures: r_opt (1) = MP2/6-311+G(d,p) optimization, and r_opt (2) = MP2/6-311+G(3df,3pd) optimization.

		Calc. (1)		Calc. (2)		Expt [1]

X_aa	-	1316.7	-	1286.3	-	1294.041(34)
X_bb		399.5		382.6		380.05(6)
X_cc		917.2		903.7		913.99(7)
\|X_ab\|		1062.4		1056.8		1070.28(6)

RMS		17.4 (2.01 %)		7.6 (0.88 %)
RSD		15.2 (1.23 %)		15.2 (1.23 %)

X_xx		907.1		894.7		901.73(7)
X_yy		917.2		903.7		913.99(7)
X_zz	-	1824.2	-	1798.4	-	1815.72(6)
ETA		0.0055		0.0050		0.00675(6)
Ø_z,a		25.53		25.85
Ø_a,CI		24.80		25.01
Ø_z,CI		0.73		0.84


Table 2. AA-1-Iodobutane r_opt (1) = MP2/6-311+G(d,p) optimization, and r_opt (2) = MP2/6-311+G(3df,3pd) structure parameters (Å and degrees).


	C C,1,B1 H,1,B2,2,A1 H,1,B3,2,A2,3,D1,0 C,2,B4,1,A3,3,D2,0 H,2,B5,1,A4,5,D3,0 H,2,B6,1,A5,5,D4,0 C,5,B7,2,A6,1,D5,0 H,5,B8,2,A7,1,D6,0 H,5,B9,2,A8,1,D7,0 H,8,B10,5,A9,2,D8,0 H,8,B11,5,A10,2,D9,0 H,8,B12,5,A11,2,D10,0 I,1,B13,2,A12,5,D11,0

	r_opt (1)	r_opt (2)

	B1=1.5208377 B2=1.09128618 B3=1.09128618 B4=1.53138157 B5=1.09605423 B6=1.09605423 B7=1.52938283 B8=1.09702359 B9=1.09702359 B10=1.09377552 B11=1.09453679 B12=1.09453679 B13=2.1643919 A1=111.61937866 A2=111.61937866 A3=111.23007962 A4=109.67268843 A5=109.67268843 A6=112.02277218 A7=109.25249474 A8=109.25249474 A9=111.26262195 A10=110.7045248 A11=110.7045248 A12=112.42267525 D1=122.72381267 D2=-61.36190633 D3=121.35616517 D4=-121.35616517 D5=180. D6=-58.2552772 D7=58.2552772 D8=180. D9=-59.82808938 D10=59.82808938 D11=180.	B1=1.5141897 B2=1.0863845 B3=1.0863845 B4=1.52546133 B5=1.09130819 B6=1.09130819 B7=1.52356774 B8=1.09208845 B9=1.09208845 B10=1.08846948 B11=1.08943346 B12=1.08943346 B13=2.13746915 A1=111.86194525 A2=111.86194525 A3=111.01094226 A4=109.5448918 A5=109.5448918 A6=111.80889621 A7=109.29669476 A8=109.29669476 A9=111.4109689 A10=110.74389822 A11=110.74389822 A12=112.16817576 D1=122.9517858 D2=-61.4758929 D3=121.45171281 D4=-121.45171281 D5=180. D6=-58.26023789 D7=58.26023789 D8=180. D9=-59.78954841 D10=59.78954841 D11=180.


Table 3. AA-1-Iodobutane. Rotational Constants (MHz). r_opt (1) = MP2/6-311+G(d,p), and r_opt (2) = MP2/6-311+G(3df,3pd) optimization.

		r_opt(1)	r_opt(2)	Expt [1]

	A	15187.	15310.	15052.043(9)
	B	727,	740.	732.93002(18)
	C	706.	719.	711.34567(20)


Table 4. AA-1-Iodobutane. Quartic Centrifugal Distortion Constants (kHz). Calc = B3LYP/6-311+G(d,p).

			Calc		Expt [1]

	D_J		0.0411		0.0459(11)
	D_JK	-	2.57	-	2.867(17)
	D_K		164.
	d_1	-	0.00264
	d_2	-	0.00003

[1] E.A.Arsenault, D.A.Obenchain, T.A.Blake, S.A.Cooke, and S.E.Novick, J.Mol.Spect. 335,17(2017).

E.A.Arsenault, D.A.Obenchain, S.A.Cooke, T.A.Blake, and S.E.Novick, Abstract WE02, 71st International Symposium on Molecular Spectroscopy, Champaign-Urbana, Ill 2016.

CH₃I

CH₃CH₂I

trans-1-Iodopropane

gauche-1-Iodopropane

Table of Contents

Molecules/Iodine

1_Iodobutane_AA.html

Last Modified 24 July 2016